function is_pure(number)
    for i =2: sqrt(number)-1
        if number%i==0
            return false
        end
    end
    #print(number,"  is a prime number！" )
    return true
    #     if number%i==0:
    #         return False
    # else:
    #     #print(" %d is a prime number！" % number)
    #     return True
end 

f = open( "/home/lcp/LCP_LAB/julia-test/pure_number.txt", "w" )
end_num=10^6
@time for k =3:end_num
    
    if (is_pure(k)==true)
        writedlm(f, [k])
       #println(k)
    end
end
close(f)